The End of Science: Facing the Limits of Knowledge in the Twilight of the Scientific Age by John Horgan, Reading, MA: Addison-Wesley Publishing Company, Inc., 1996.

The End of a World View

When The End of Science first appeared I had no interest in reading it. The title suggested an exercise in the fashionable practice of science-bashing, an activity which interests me but little. However, the other day I found myself standing in the new books section of the local library and there, an arm's length away, was Horgan's book. I reached out, grabbed the book, and took a quick look through the table of contents, which displayed an interesting range of names and topics. I decided to borrow the book. If it proved annoying I didn't have a sales slip to remind me of my error.

Though Horgan has, in fact, proved to be annoying, I haven't allowed that to keep me from finishing his book. The major attraction is that Horgan, a senior writer for Scientific American, covers a wide range of areas--particle physics, cosmology, biology, neuroscience, artificial intelligence, a bit of the social sciences, complexity, philosophy of science, and others here and there--asking prominent people what they see beyond the edges of the work their fields are actually delivering to the technical literature. Though, like many readers of this journal, I have a specialist's interest in some of this work, I also have a citizen's interest in the general state of scientific knowledge. Reading Horgan's book is an excellent way to review a citizen's science in a few evenings or over a weekend.

Whether you begin The End at the beginning, or, as I did, by reading the sections most directly related to your current interests, you quickly discover that Horgan passionately believes science to be a search for the truth, a search that has been gratifyingly successful. Horgan doesn't believe that objectivity is a hoax, that the sciences are no more true than astrology or literary criticism. Horgan doesn't even bother to grapple with any of the arguments which have been advanced about the impossibility of objectivity. He accepts scientific truth at face value. But he also believes that the stock of fundamental scientific truths is limited and that we have discovered most of them. The glory days of basic discovery are over. Now that the continents have been discovered and mapped the explorers can retire to the rest home and leave the world in the hands of real estate developers.

I think Horgan is wrong, and so do many of the investigators he interviewed. However, he always manages to come up with reasons to discount their disagreement. One of these scientists, Stuart Kauffman, points this out in an online debate in HotWired magazine, citing Horgan's treatment of the linguist Noam Chomsky as being typical (Horgan & Kauffman, 1996). Chomsky believes that there is a great deal of science before us, and Horgan dismisses him by asserting that "...I suspect he was really succumbing to wishful thinking. Like so many other scientists, he cannot imagine a world without science" (p. 153). In one way or another Horgan uses this or a similar gambit time after time, and that is my chief annoyance with his book. Horgan is most comfortable with scientists like Gunter Stent, a biologist whose metascientific musings are at the heart of his enterprise, who agree that most of the science has been done, or the philosopher Colin McGinn, who believes that we are up against fundamental limits in our cognitive capacities which will make it impossible for us to venture beyond the truths we've already staked out. Of course I have no way of proving that Horgan is wrong, and perhaps that is the root of my annoyance.

However, I would prefer to think my annoyance is a bit more subtle, and it has to do with authority, a big topic in the post-modern intellectual agenda. Where do arguments get their authority? Scientific arguments, so the standard theory goes, get their authority from the interaction of logical reasoning and empirical evidence. While post-modern intellectuals question that account, Horgan himself seems not to and I have no desire to do so either. But arguments about the nature of science are not themselves scientific arguments. They are "meta" to science and Horgan knows that. So where do such arguments get their authority? Well, if they are made by professional philosophers and presented in philosophical journals, they get their authority from philosophical reasoning, whatever that is. But Horgan is not a philosopher and he's not making his argument in a philosophical way.

Horgan is a journalist and he is summoning authority for his argument from the scientists themselves. Whatever his reason for making this argument--which has something to do with a frightening ecstatic experience he once had (p. 261)--his major evidence is that scientists themselves believe their enterprise to be near its end. Given that, he has to do something about scientists who believe that there's much fundamental science in the future. What he does is simply discounts their faith by attributing their belief to ulterior motive rather than to clear-sighted assessment of the current scene.

Anyone who disagrees with Horgan is, of course, free to use the same tactic. And indeed, one of the thinkers Horgan interviews does just that. The man is Gregory Chaitin, an IBM mathematician. When Horgan lays out the end of science argument which Gunther Stent had made, Chaitin wonders whether or not Stent had a liver problem or had lost a girlfriend at the time he made the argument. When Horgan tells Chaitin that Stent made his argument when he was at Berkeley in the 1960s, that tells Chaitin all he needs to know about the source of Stent's pessimism (p. 240). While I don't find Chaitin's discounting of Stent any more or less convincing than Horgan's discounting of Chomsky, the point is that it is a fairly trivial matter to play this game.

All of this is so obvious that Horgan's particular bias need be no more than an annoyance to those who think he's wrong. However, I think there is more at stake than simply pointing out that one can apply different ad hominem discounts to the testimony of his informants and reach the opposite conclusion, that science will enjoy continued growth in the future. One can read The End of Science as evidence of the emergence of a new worldview. Those, like Horgan, who believe that science is indeed coming to an end are heirs of standard Western metaphysical assumptions, assumptions which are in a shambles. Those who believe that science has a splendid future are helping to forge an as-yet unnamed worldview, one grounded in different assumptions, though, perhaps more often than not, the people working toward this worldview think of it as but a continuation of the Western worldview they were taught in school.

The Old World: A Simple Universe

The basic assumption behind Horgan's argument, and behind much of Western thought, is that the world is basically simple. The thinker's job is to look behind the ephemeral polymorphic plenitude of phenomenon to discern the basic laws at the heart of reality. Those laws are relatively few in number. When those laws have been discovered--one, two, three, four and so forth up to the last one--we will have The Answer, as Horgan calls it. With The Answer in hand, we can then work out all the little details, and do a lot of mere engineering to take advantage of the fact that we now know all that is knowable. Note that while Horgan doesn't preface "engineering" with "mere," that does seem to be his attitude when he talks of engineering, or, as he often does, applied science. Pure science is a noble undertaking, but engineering is not. While lots of mental work remains to be done, it is not so august as the scientific pursuit of The Answer.

Horgan extends this assumption in various ways. One is the idea of cognitive limits; there are things which are inherently beyond the capacity of our brain to comprehend. This implies that there is lawful activity in the universe which we cannot discover because our brains cannot think the laws which explicate that activity; for without that lawful activity, our inability to think the thoughts would be of no consequence. Thus, simple as the universe is, some of the basic laws may remain forever beyond our comprehension.

Then there is the more mundane problem of the expense of scientific investigation. In some disciplines, particle physics for example, the experimental apparatus costs billions and billions of dollars. Society seems less and less willing to foot the bill for doing this science. Thus in 1993 the United States Congress had decided to stop funding the superconducting supercollider. A number of Horgan's interviews with physicists took place in the wake of this decision and they were understandably glum, for it meant that a various theories would remain untested by experiment. This limitation, of course, is merely practical; it says nothing about limits to human cognition or about the basic nature of the universe. This merely practical consideration does, however, set limits on what thinkers can do in what little room the universe makes for their activities.

There is, however, something else we must consider while thinking about this merely practical matter of money and social will. The assumption of the simple universe is generally accompanied by a belief in reductionism. To the extent that the phenomena of biology, psychology, sociology, linguistics, and so forth, are knowable, that knowledge is ultimately reducible to the laws of physics and chemistry, or perhaps just physics. An unwillingness to spend money to investigate physics thus has repercussions through all the disciplines, which are to be reduced to physics. However, no one in this book, or anywhere else that I know of, is suggesting that linguistics, for example, is waiting for results in particle physics before it can proceed in some crucial area of investigation. Yet the reductionist view implies that such must be the case sooner or later. In this context an unwillingness to spend money on supercolliders and such threatens, not just physics, but all of human knowledge, at least that which isn't mere detail and engineering.

But reductionism, and the simple universe which it finds most convenient, isn't the only game in town.

A New World: The Fecund Universe

One of the people Horgan talked to is Paul Feyerabend, the well-known philosopher of science. At the time Feyerabend was working on his autobiography (Killing Time) and on another philosophy book, one he was unable to complete before he died.

Tentatively titled The Conquest of Abundance, it addressed the human passion for reductionism. "All human enterprises," Feyerabend explained, seek to reduce the natural diversity, or "abundance," inherent in reality. "First of all the perceptual system cuts down this abundance or you wouldn't survive." Religion, science, politics, and philosophy represent our attempts to compress reality still further. Of course, these attempts to conquer abundance simply create new abundances, new complexities.

This has the feel of the emerging world view, especially the line asserting that "these attempts to conquer abundance simply create new abundances." That abundance is what the new view is about. It is a topic the late David Hays and I discussed under the rubric of fecundity--Hays suggested the term--and that is the word I shall use. I have no particular reason to believe that our discussions paralleled Feyerabend's ideas in any detailed way, but "abundance" and "fecundity" share a thematic similarity.

Let us start with an analogy. Consider the game of chess. It has a finite number of pieces and is played on a board which is finite in size; the rules governing play are finite in number and restrict each move to a finite number of steps; and all games must end in a finite number of steps, though it is possible for a game to end in a draw. Thus described chess is an inherently simple game. And yet it is rich enough to tax the abilities of very intelligent and creative people who devote their lives to playing it. A substantial community of people devotes a great deal of time and effort, not only to playing chess, but to studying it and teaching it, writing books and articles and, in the last half-century, programming computers to play the game.

The devotees of the simple world are like those who think that, when you know the rules of chess, you know all there is to know about the game. All the rest is either mere appearance, mere contingency, or mere engineering; whatever it is, it is only merely so. To the devotees of fecundity the rules are only the starting point and all the rest, that is what we must understand. And, more to the point, that is what we can understand, if not just yet, and not necessarily exhaustively and finally.

Of course we need to look beneath the surface of things. But there is no reason to think that what we will find will be simple. On the contrary, I believe that complexity inheres in the basic fabric of nature (Benzon & Hays 1990a). That complexity is necessary and not contingent. It is that inherent complexity which makes the universe so fecund, so full of abundances.

Fecundity is about the capacity of one Realm of Being to give rise to another Realm. In a fairly standard version--see Horgan's account of the views of physicist Philip Anderson, one of the founders of the Santa Fe Institute (pp. 209-210)--the inorganic gives rise to the realm of life; life gives rise to mind; and mind perhaps gives rise to culture. Culture may well give rise to something else, and that something else will in turn give rise to something yet all-together new, and so forth. The laws of a higher realm must be consistent with those of the lower realms, but they are not derived from those laws. Each realm has its own laws, and there is no inherent limit to the number of realms. Hence there is no reason to believe that the universe is inadequate to our cognitive needs.

The relationship between a higher realm and the one(s) which gave rise to it can be said to be one of implementation.1 The term is from computing and designates a phenomenon which is ubiquitous there. A computer is, of course, a physical device, a complex bit of engineering. The nature of these devices has changed considerably in computing's short history, from mechanical relays and vacuum tubes in the 1940s and 1950s to transistors and integrated circuits in the 1960s and 1970s to ever denser microchips starting in the late 1970s and continuing to this day and on into the future, though not very far into the future--just what technologies will supplant microchips is not at all certain, but many things are in the works. In order for these circuits to compute anything they must implement certain logical functions. The nature of those functions is quite independent of the medium in which they are implemented. Nor can one in any meaningful way reduce the logical function of a circuit to the physical laws of the device implementing the circuit. Those physical laws tell you what will happen at a certain point Q when the voltage goes above a certain value, but they tell you nothing about why Q is connected to O and P and R and S in a certain way. That pattern of connections is dictated by logic, not physics.

The implementation of logical functions in physical circuits is only one side of implementation, the hardware side. Most implementation is on the software side. High-level languages are implemented in assembly language and end-user programs are implemented in high-level languages. Currently one of the most popular languages is one called C, with a sibling called C++. It requires one implementation to run on a "Wintel" machine, one for the Macintosh, another for a Sun Sparcstation, and so forth. The C language is the same in each case; it has the same nouns and verbs. But the assembly language which implements those nouns and verbs is specific to the machine it runs on. Further, the assembly language for a given machine can implement the nouns and verbs of other high-level languages, such as Basic, Pascal, Fortran, or Cobol. The fact that one language is used to implement another is in not the same as asserting that the high-level language is reducible to the lower level language. Each language establishes its own domain, its own realm; implementation is the relationship between one realm and another.

Of course, it is one thing to explore implementation in the world of computing. It is rather different to assert that the relationship between biology on the one hand and physics and chemistry, on the other, is one of implementation. That requires an argument which I am not prepared to make, though some practitioners of artificial intelligence and artificial life seem to take it as a matter of faith. Given the work that Hays and I did on natural intelligence (Benzon & Hays 1988) I feel a little more confidence about the relationship between psychology and neurobiology; for that article proposed five principles governing the implementation of mind in brain. The most ambitious research program under the aegis of AI is about the implementation of mind in computer. However doubtful I am about what AI has so far achieved--Horgan quotes Marvin Minsky as asserting that consciousness is a trivial matter he resolved long ago (p. 184)--that goal doesn't seem to be inherently problematic. However mind operates, it is a realm unto itself. Its laws are not reducible to those of biology or those of computing, though it may well be possible that they can be implemented in either. Beyond mind, David Hays and I have speculated in personal conversation that the phenomena of social role (Linton 1935) and double-contingency social interaction (Parsons 1951) are the seeds of a new realm which we might as well call culture. We could then say that culture is implemented in mind, though explicating that is another matter entirely.

If this is how the universe operates then the closest one could come to what Horgan calls The Answer would be to understand how one realm could give rise to another. That is perhaps where Ilya Prigogine's work comes into play (Horgan, pp. 216-221; Benzon & Hays, 1990a, pp. 36-37). However, while Horgan's Answer is complete unto itself, the Answer implied by Prigogine's work assures us only that the universe generates yet further fundamental questions.

The Evolving Mind

But what of our capacity to answer those questions? Both Colin McGinn, a philosopher (pp. 57-58), and Noam Chomsky, a linguist (pp. 151-153), think there are inherent limits to human thought which are posed by human biology, though McGinn is a pessimist while Chomsky is an optimist about our intellectual future. Following Chomsky Horgan asks us to contemplate a rat in a maze, noting that the rat's brain limits its cognitive abilities in such a way that it cannot solve mazes. By analogy, our own cognitive abilities must be subject to similar limitations.

I'm not quite sure what to make of this argument. If it is true, that would certainly explain why some areas of investigation aren't going well. But then 500 years ago, for example, chemistry wasn't going so well and look what happened. That's not much of an argument either. In any even, it would seem hubristic to dismiss this line of speculation entirely. And computers certainly show, that in many tasks, they outperform us perhaps by as great a margin as we outperform rats in the task of running mazes.

Let us come at the issue from a different starting point. Freeman Dyson tells Horgan (pp. 254-255) that "I think these people who predict the end of physics may be right in the long run. Physics may become obsolete. But I would guess myself that physics might be considered something like Greek science: an interesting beginning but it didn't really get to the main point. So the end of physics may be the beginning of something else." Physics is thus a particular kind of inquiry into the nature of the universe and it may well come to an end, only to be superseded by a more sophisticated inquiry, one which goes about its business in a deeper way than physics did. This ending is quite different from Horgan's, which imagines that little or no significant inquiry remains possible after the end of science.

I like this suggestion, and for the most self-serving of reasons: it is consistent with my own thinking. David Hays and I have argued (1990b) that human reasoning has so far been based on 4 different broad classes of paradigms, which we call ranks, with each rank based on a different cognitive process. The processes are ordered such that the process for the Rank 4 paradigms presuppose the processes for the other three; Rank 3 presupposes the first two; and Rank 2 presupposes Rank 1. Rank 1 paradigms are based on the process of abstraction, which is inherent in language (cf. Benzon & Hays, 1988, pp. 317-319). The Rank 2 process is rationalization and it arises in the wake of writing; this is where we find Greek science. The Rank 3 process is theorization and it is grounded in algorithmic calculation; here we find the rise of modern science. Model-building is the Rank 4 process and is grounded in computing. It is this fourth process which Dyson intimates may simply give rise to an entirely new way of thinking about the world.

If one assumes that knowledge is constructed, then one might well inquire about the nature of the tools the mind uses for creating these constructions. Each of those processes requires different mental mechanisms, even different patterns of gross brain activity. Abstraction alone can penetrate only so deeply into the world before it ceases to produce useful accounts. With the emergence of rationalization, thought can penetrate still more deeply, and so with the other two processes. For each process that is added to the conceptual repertoire another "layer" of reality becomes susceptible to thought and control. At each stage in cognitive evolution there are limits to knowlege. But there is nothing I can see that limits the number of fundamental conceptual processes we can create for ourselves. If "science" seems to be coming to an end, that may only reflect the limits of our current suite of processes for constructing theories and tests.

One of the things a number of Horgan's informants asserted was that, in the words of Mitchell Feigenbaum "We are building tools" (p. 224). By tools they mean concepts and modeling techniques, ways of thinking. What reason have we to think that more tools will not be built? If it is hubristic to dismiss out of hand the possibility that our mind has limitations, it also seems hubristic to dismiss out of hand the possibility of inventing more tools which allow us to extend our minds beyond the scope previously thought possible and prudent. We are talking about the future, and the future cannot be readily extrapolated from the past. That we shall overcome limitation seems as possible as limitation overcoming us.

Where does this leave us?

The argument I have made in the previous two sections is, as these things go, perhaps only a bit more explicit than what one could piece together from comments in Horgan's text. Many of the thinkers Horgan has investigated have similar sentiments, more than is practical to cite in detail. Such ideas are in the air. That does not, of course, make them right--confidence in UFO landings is also in the air. But it goes a ways toward taking the edge off of Horgan's various ad hominem dismissals. Perhaps we are all indulging ulterior motives, but at least we can do so together, as an intellectual community.

And perhaps we can do a little better than that. Horgan seems unaware of the possiblity that his views are grounded in a particular set of assumptions about the world and about knowledge, albeit widely shared assumptions. Like all such assumptions these are contingent, they are tied to a particular history enacted in a particular cultural arena. In the term Hays and I have used, these are the assumptions of the Rank 3 clock-work universe (Benzon & Hays, 1990b, pp. 310-311). The notion of fecundity, on the other hand, seems more appropriate as the underpinning of Rank 4 thinking, which cut its teeth on phenomenon irreversibly enmeshed in time, thermodynamics and evolution (Benzon & Hays, 1990b, pp. 312-313). Thus one might contemplate an argument explicitly analyzing how the notion of the fecund universe is more sophisticated than that of the simple universe; one might conduct this analysis using some of the tools of cognitive science (e.g. Hays, 1976, Gentner & Stevens, 1983, Benzon 1986). Such an argument, I submit, would put this issue on a different footing. For it would amount to saying that Horgan is operating with a set of cognitive tools which is distinctly more limited than the set employed by those who see a bright future ahead. If that is the case, then why should we attend to his arguments for any purpose other than that of sharpening our own?

Notes

1. This use of the concept of implementation comes from conversations with David Hays and Richard Fritzson.